JPH05226460A - Semiconductor chip position detecting device by processing image - Google Patents

Abstract

PURPOSE:To accurately detect the position of a semiconductor chip mounted on a stage or the like in a semiconductor device manufacturing process. CONSTITUTION:A zoom lens is mounted on a TV camera, at first an image of wide area is picked up by a TV camera of low magnifying power to recognize a semiconductor chip 1 detected on a CRT scope 2, and the coordinate deviations X1 and Y1 of a chip center O from a coordinate reference point 3 are detected. Then, the TV camera is moved by a distance of X1 and Y1 and switched to a high power, then the image of the semiconductor chip 1 is picked up again by the TV camera of high power to recognize the chip 1 for detecting the coordinate deviations X2, and Y1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor chip position detecting method by image processing, and more particularly to recognizing an image on a CRT screen using a TV camera for an object semiconductor chip.

[0002]

2. Description of the Related Art In many manufacturing processes of semiconductor devices, it is important to accurately detect the position of a semiconductor chip mounted on a stage. In the conventional method of detecting the position of a semiconductor chip to be detected, for example, a semiconductor camera is imaged using a TV camera equipped with a lens having a fixed magnification of the required detection position accuracy, and the image is displayed on a CRT screen 2 as shown in FIG. In order to recognize the coordinates of the center point 0 of the image of the semiconductor chip 1 formed as the position of the center point of the CRT screen with respect to the coordinate reference point 3,
The coordinate shift amounts X and Y are detected by image processing.

In this case, the higher the lens magnification of the TV camera, the narrower the imaging range shown in the CRT image 2, but the higher the detection accuracy. Further, the lower the lens magnification, the wider the imaging range, but the lower the detection accuracy.

[0004]

In this conventional method for detecting the position of a semiconductor chip by image processing, it is necessary that the entire image of the semiconductor chip to be detected is largely projected on the CRT screen in order to improve the detection accuracy. is there.

For this reason, the amount of deviation between the position of the semiconductor chip to be detected and the TV camera is enlarged, and the lens is likely to be out of the imaging range of the lens. In that case, the semiconductor chip to be detected cannot be easily recognized and the detection time is long. There was a problem.

[0006]

According to a semiconductor chip position detecting method by image processing of the present invention, a zoom lens is attached and a TV camera for image pickup is used. First, the lens magnification of the zoom lens is reduced to a low semiconductor chip to be detected. Is detected to roughly detect the position of the semiconductor chip to be detected, and then the focus of the TV camera for imaging is moved to a position near the center of the detected chip. It is configured by imaging the semiconductor chip to be detected again after switching to.

[0007]

The present invention will be described below with reference to the drawings. FIGS. 1A to 1C are CRT screen diagrams in the order of detection steps for explaining the first embodiment of the present invention.

First, as shown in FIG. 1 (a), the lens magnification is set to a low magnification, the semiconductor chip 1 to be detected having a chip center point 0 is imaged, and the center with respect to the coordinate reference point 3 in the CRT screen 2 is imaged. The shift amounts X1 and Y1 at point 0 are detected in the same manner as in the conventional case.

Next, as shown in FIG. 1B, the camera is set so that the center 0 of the semiconductor chip 1 to be detected is substantially located at the reference point 3 based on the deviations X1 and Y1 of the center point 0. Move and perform coarse positioning.

Next, as shown in FIG. 1C, the lens magnification is set to a high magnification, the semiconductor chip 1 to be detected is imaged up again, and the deviation amount X2, Y of the central point 0 from the reference point 3 is taken.
2 is detected with high precision.

FIGS. 2A to 2C are CRT screen diagrams in the order of detection steps for explaining the second embodiment of the present invention.
As shown in FIG. 2A, it is assumed that the A pattern 4 and the B pattern 5 of the detected semiconductor IC 1a are fixed at the relative coordinate positions XP and YP.

First, similarly to the above, the magnification is set to a low magnification, the detected IC chip 1a is imaged by the TV camera, and the deviation amounts X1 and Y1 of the pattern center point 0 with respect to the reference point 3 of the A pattern 4 are detected. ..

Next, as shown in FIG. 2B, the deviation amounts X1, Y1 detected in the previous step and the A pattern 4 and the B pattern 5 are detected.
The positions (X1 + XP) and (Y1 + YP) of the B pattern 5 are calculated based on the relative positions XP and YP of the reference point 3
The camera is moved so that the B pattern 5 is positioned at the position, and coarse positioning is performed.

Next, as shown in FIG. 2C, the lens magnification is set to a high magnification and the IC chip 1a to be detected is imaged again,
The deviation amounts X2 and Y2 of the B pattern 5 from the reference point 3 are detected with high accuracy.

[0015]

As described above, according to the present invention, the zoom lens is attached to the TV camera, the semiconductor chip to be detected is imaged at a low lens magnification to detect the position, and then the TV camera is located at the detected position. Is moved to switch the lens magnification to a high magnification, and the position of the semiconductor chip to be detected can be detected with a wide range and with high accuracy by detecting the image of the semiconductor to be detected and detecting the position again.

[Brief description of drawings]

FIG. 1A to FIG. 1C are CRT screen diagrams in the order of detection steps for explaining a first embodiment of the present invention.

2A to 2C are CRT screen diagrams in the order of detection steps for explaining a second embodiment of the present invention.

FIG. 3 is a CRT for explaining an example of a semiconductor chip position detecting method by image processing of a conventional position detecting method.
It is a screen figure.

[Explanation of symbols]

 1, 1a Detected semiconductor chip 2 CRT screen 3 Coordinate reference point 4 A pattern 5 B pattern 6 CRT coordinate line

Claims (1)

[Claims] 1. A zoom lens is attached to a TV camera for image pickup, and the lens magnification of the zoom lens is first set to a low magnification to image a wide area including a semiconductor chip to be detected to roughly detect the position of the semiconductor chip to be detected. Then, after moving the focal point of the imaging TV camera to a position near the center of the detected chip, the lens magnification is switched to a high magnification and the semiconductor chip to be detected is imaged again. Semiconductor chip position detection method by processing.